Bump langchain-core from 1.2.9 to 1.2.11 (#176)

Bumps [langchain-core](https://github.com/langchain-ai/langchain) from 1.2.9 to 1.2.11.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-core==1.2.9...langchain-core==1.2.11)

---
updated-dependencies:
- dependency-name: langchain-core
  dependency-version: 1.2.11
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Nikhil Navakiran <nikhil.navakiran@gmail.com>

Author: dependabot[bot]